PART 2 , S ECT ION C, RUL E 18 : TACK ING, GY B ING & OTHE R EXCE P T IONS 203
Second, the two boats must have been on opposite tacks, and the port-tack boat (P) must have tacked to starboard tack, passing head to wind in the zone. Third, P must be fetching the mark after her tack. “Fetching” means a boat can pass to windward of a mark leaving it on the required side without sailing past head to wind to do so (see the definition Fetching). Finally, the starboard-tack boat (S) must have been on starboard tack since she entered the zone; if she had entered the zone on port tack and then tacked to starboard tack, rule 18.3 does not apply. And when rule 18.3 applies, rule 18.2 (Giving Mark-Room) does not apply (see rule 18.3). Note that when P and S are approaching the mark, rule 18 doesn’t apply at
all because the boats are on opposite tacks on a beat to windward (rule 18.1(a), When Rule 18 Applies). Furthermore, if P passes head to wind outside the zone and then completes her tack inside the zone, rule 18.3 does not apply. However, rule 13 (While Tacking) applies, and if S needs to avoid P before she completes her tack (gets to a close-hauled course), P has broken rule 13. It can be argued that it is difficult to know exactly where the zone is, but that is the case when applying the zone in any mark rounding or passing situation. Sailors approach - ing port-hand windward marks on port tackwill be well advised to be conserva -
